1. Garey, M. R., and Johnson, D. S., Computers and Intractability: A Guide to the Theory of NP-Completeness, W. H. Freeman, San Francisco, California, 1979.
2. Beck, A. and Teboulle, M., Global Optimality Conditions for Quadratic with Binary Constraints, SIAM Journal on Optimization, Vol. 11, pp. 179–188, 2000.
3. Bertsekas, D. P., Nonlinear Programming, Athena Scientific, Belmont, Massachusetts, 1995; see 2nd Edition, 1999.
4. Luenberger, D. G., Optimization by Vector Space Methods, John Wiley, New York, NY, 1969.
5. Rockafellar, R. T., Convex Analysis, Princeton University Press, Princeton, New Jersey, 1970.